<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>伪元素选择器</title>
    <style>
        div{
            width: 200px;
            height: 200px;
            background-color: pink;
        }
        /* ：：before是行内元素 且权重为1*/
        div::before{
            content: "我";
            width: 30px;
            height: 30px;
            background-color: limegreen;
            /* 转换成行内块元素 */
            display: inline-block;
        }
        div::after{
            content:"银杏树";
        }
        
    </style>
</head>
<body>
    <div>是</div>
</body>
</html>